I consider it a unicycle because of the word etymology. uni "one" + cycle, from Greek kyklos "circle, wheel".

Some guy showed up to the first meetup asserting that it was a "bc wheel", which I later learned is from the old B.C. comics strip: https://en.wikipedia.org/wiki/Impossible_wheel

I used to love those comics with cave people riding on wheels. Maybe that's why I like these things.

With regards to practice, it took me 2 weeks to learn well enough to travel a few blocks around the neighborhood. Other people learn faster. Many people come to the meetup and go a few feet on their first day.